Devices made on α‐Sn thin films on CdTe(111) are of particular interest in the context of topological electronics due to the insulating nature and hexagonal projection of the epitaxial substrate. Ultrathin topological insulating films require pristine preparation of the CdTe surface, and a capping layer before ex situ fabrication can be performed. Theoretical studies have identified a topological semimetal regime that can be addressed with intermediate thin‐film thicknesses that are robust enough to process into devices. Magnetotransport devices using uncapped epitaxial α‐Sn thin films grown on CdTe(111)B and characterization of the growth that provides context for these results are reported. Noninvasive techniques verify the pseduomorphic growth of the films before fabrication of mesoscopic devices. A transition to a 3D metallic scaling behavior at low temperature—with large magnetoresistance, high mobility, and quantum oscillations with anomlous transport characteristics that are significantly different from previous results on α‐Sn thin films—is identified. A parallel p‐type dopant channel with high carrier density is seen to dominate at thinner film thicknesses, indicating that careful preparation of the CdTe surface before growth is crucial to attain a low dopant density and accessible topological states on an insulating substrate.